III. Ecosmos: A Revolutionary Fertile, Habitable, Solar-Bioplanet Lifescape
1. Quantum Cosmology Theoretic Unity
Habib, Salman, et al.
HACC: Extreme Scaling and Performance across Diverse Architectures.
Communications of the ACM.
A 13 member team from Argonne, Los Alamos, and Berkeley Lawrence National Laboratories describe frontier computational capacities by which our worldwide sapience can achieve a cosmic self-quantification of infinite celestial environs.
Supercomputing is evolving toward hybrid and accelerator-based architectures with millions of cores. The Hardware/Hybrid Accelerated Cosmology Code (HACC) framework exploits this diverse landscape at the largest scales of problem size, obtaining high scalability and sustained performance. Developed to satisfy the science requirements of cosmological surveys, HACC melds particle and grid methods using a novel algorithmic structure that flexibly maps across architectures, including CPU/GPU, multi/many-core, and Blue Gene systems. In this Research Highlight, we demonstrate the success of HACC on two very different machines, the CPU/GPU system Titan and the BG/Q systems Sequoia and Mira, attaining very high levels of scalable performance. (Abstract)
Hartle, James. Arrows of Time and Initial and Final Conditions in the Quantum Mechanics of Closed Systems Like the Universe. arXiv:2002.07093. We choose this recent entry by the UC Santa Barbara physicist to recognize his decadal flow of papers about the so mathematical matters of melding quantum depths with cosmic breadth. The third abstract is from a 1990 Jerusalem Winter School and well catches this human unification of depth and breadth. See also, for example, The Impact of Cosmology on Quantum Mechanics (1901.03933) and The Quantum Mechanics of Cosmology (1805.12246), abstracts below, for his oriented agenda.
In a quantum universe, arrows of time are described by the probabilities of appropriately coarse grained sets of histories of quantities like entropy that grow or decay. We show that the requirement of that these sets of histories decohere implies two things: (1) A time asymmetry between initial and final conditions that is a basis for arrows ot time. (2) How a final state of indifference that is represented by a final density matrix proportional to the unit density matrix is consistent with causality, and allows a finer-grained description of the model universe in terms of decoherent histories than any other final state. (Abstract, 2002.07093)
Hartle, James. How Nature is Conformable to Herself: A View from Quantum Cosmology. arXiv:1909.08724. The UC Santa Barbara physicist and often collaborator with his advisor the late Nobel laureate Murray Gell-Mann (1929-2019) comments on his 1996 article with the above title (Complexity 1/4) in which he, as did Newton from whom the phrase comes, avers a persistent innate recurrence in kind from universe to us. A metaphor is layers of onion skin – a natural genesis conforms to and reiterates the same “complex adaptive system” at each and every stage (see his 1994 The Quark and the Jaguar). Circa 2019, Hartle indeed cites a universality of emergent, mathematical simplicity, regularity and complexity from its quantum dynamics source. See George Johnson’s N. Y. Times obit (May 25) where he also notes Murray’s long advocacy of a sensible cosmos which opens to our comprehension.
In his essay "Nature Conformable to Herself" the late Murray Gell-Mann expands on an observation of Newton that theories of seemingly disparate phenomena in the universe often make use of similar ideas and similar mathematical structure. Newton summarized that by saying that nature was very consonant and conformable to herself. This essay uses a model of quantum cosmology to illustrate how, why, and when nature is conformable to herself. (Hartle Abstract)
Hartle, James, et al. Accelerated Expansion from Negative Lambda. arXiv:1205.3807. Coauthors are Stephen Hawking and Thomas Hertog, posted on May 30, 2012. As reported by Amanda Gefter in New Scientist for June 30, noted above, a proposal by these veteran physicists to resolve piled up inconsistencies with older inflationary and string theories by way of a holographic theory solution.
Wave functions specifying a quantum state of the universe must satisfy the constraints of general relativity, in particular the Wheeler-DeWitt equation (WDWE).We show for a wide class of models with non-zero cosmological constant that solutions of the WDWE exhibit a universal semiclassical asymptotic structure for large spatial volumes. A consequence of this asymptotic structure is that a wave function in a gravitational theory with a negative cosmological constant can predict an ensemble of asymptotically classical histories which expand with a positive effective cosmological constant. This raises the possibility that even fundamental theories with a negative cosmological constant can be consistent with our low-energy observations of a classical, accelerating universe. We illustrate this general framework with the specific example of the no-boundary wave function in its holographic form. The implications of these results for model building in string cosmology are discussed. (Abstract)
Hattich, Frank. Quantum Processes: A Whiteheadian Interpretation of Quantum Field Theory. Munster: agenda Verlag, 2004. Wherein a physicist and philosopher methodically finds the mathematical formalism of QFT to imply that rather than particles and fields, fluid processes are the essence of reality. In Alfred North’s terms, these dynamics result in a self-creating, self-causing, and self-realizing universe.
Hawking, Stephen. A Brief History of Relativity. Time. December 31, 1999. The British physicist and author provides succinct review of modern physics as written for the Albert Einstein “Person of the Century” issue.
Hawking, Stephen. Godel and the End of Physics. http://www.damtp.cam.ac.uk/strings02/dirac/hawking. A talk of March 9, 2009 at Texas A&M University at the inauguration of its Mitchell Institute for Fundamental Physics. Hawking sets aside his advocacy of a final theory that natural reality could be reduced to, for this has not worked out. The upshot is a particulate physics in conceptual disarray. Quantum gravity is central to the remedy, along with a recognition of black hole information limits. And please note herein Stuart Kauffman’s new essay “Towards a Post Reductionist Science: The Open Universe” which takes off from Hawking to propose a Darwinian kind of cosmic emergence.
Hawking, Stephen and Leonard Mlodinow. The Grand Design. New York: Bantam, 2010. When I thought it could not get worse appears this year’s science bestseller with a final paragraph epitaph. One wonders how much is due to the iconic Hawking, or Mlodinow, whose prior book was the Drunkard’s Walk about how nature’s hopeless unpredictability. The present work has rightly been denounced as neither Grand nor a Design, the muddled last hurrah of a Ptolemaic physics. Are people just “mere,” or infinitely more in a Copernican genesis universe?
M-theory is the unified theory Einstein was hoping to find. The fact that we human beings – who are ourselves mere collections of fundamental particles of nature – have been able to come this close to an understanding of the laws governing us and our universe is a great triumph. (181)
Hawking, Stephen and Thomas Hertog. Populating the Landscape: A Top-Down Approach. Physical Review D. 73/123527, 2006. The legendary British physicist, in collaboration with CERN researcher Hertog, argue that a better way to contemplate our evolving cosmos is from what (or whom) it has developed into, namely we as observers, rather than assuming all states to be determined by and follow from particular initial conditions. This important if difficult paper is reviewed in Science. 442/988, 2006, Physics Today. October 2006, 9, and Physics World. August 2006, 4.
A central idea that underlies the top-down approach is the interplay between the fundamental laws of nature and the operation of chance in a quantum universe. In top-down cosmology, the structure and complexity of alternative universes in the landscape is predictable from first principles to some extent, but also determined by the outcome of quantum accidents over the course of their histories. (123527-8)
Hogan, Craig. The Beginning of Time. Science. 295/2223, 2002. The latest observations from the COBE and MAP satellites connect cosmos and quantum through a vast inflation of the universe in its first instants. These findings accord with the multiverse scenario along with its holographic properties.
The blotchy pattern in the map, which represents tiny variations in radiation brightness, is caused by small-amplitude perturbations in the structure of space-time that stretch across billions of light years of space today; they are the largest structures we will ever be able to see…It now seems likely that these structures may also be magnified images of the smallest things we will ever be able to see. The pattern is a faithful image of quantum fields - individual elementary particles whose imprint was frozen into the fabric of space-time very early and was then stretched to enormous size by cosmic expansion. Similar fluctuations led to the gravitational formation of all astronomical structure we see today, including our own Galaxy and its stars and planets. (2223)
Ibata, Rodrigo and Geraint Lewis. The Cosmic Web in Our Own Backyard. Science. 319/50, 2008. Celestial matter has been lately found to form an intricate, thickening pattern in the likeness of a filamentary network. This lead article in a special section discusses its presence and implications in our galactic neighborhood.
Ijjas, Anna. Numerical Relativity as a New Tool for Fundamental Cosmology. arXiv:2201.03752. The astrophysicist author is presently at the NYU Center for Cosmology and Particle Physics, after stints at Princeton University, MPI Gravitational Physics and elsewhere. Here she as one woman proposes a complementary mathematical approach by which to expand and advance this celestial Earthwise project to quantify and describe the depth and breadth of our galactic universe. See also The End of Expansion by AI, Cosmin Andrei and Paul Steinhardt at 2201.07704.
Advances in our understanding of the origin, evolution and structure of the universe have long been driven by cosmological perturbation theory, model building and effective field theory. In this review, we introduce numerical relativity as a powerful new complementary method. To illustrate its power, we discuss applications to the robustness of slow contraction and inflation in homogenizing, isotropizing and flattening the universe from generic original conditions. These studies have revealed a novel, non-linear smoothing based on ultralocality that challenges the conventional view on what is required to explain the large-scale homogeneity and isotropy of the observable universe. (Abstract)